234 



Illustrations in British Zoology, 



25 



jrw 



9 



a, Outline figure of S. Dentalii, removed from the shell, and the proboscis extruded; natural 

 size, b, The same, magnified, c, The apex of the proboscis, more highly magnified, to show 

 the retroverted prickles, and its globular shape, d, A minute portion of the skin, magnified, 

 to show the form of the suckers. 



been since fully described, from specimens communicated by 

 Mr. Clift, from Yorkshire, in the Spicilegia Zoologica of Mr. 

 Gray ; a naturalist, for the extent and accuracy of his know- 

 ledge in zoology, second to none ; and whose kind and en- 

 couraging attentions I, as a learner, have so often experienced, 

 that I willingly avail myself of this opportunity to acknow- 

 ledge them. 



Although I can add nothing of value to Mr. Gray's 

 description, yet I may render it more clear and impressive to 

 your readers by the aid of a figure, which the worm seems to 

 merit, not so much on account of rarity or beauty, as from 

 certain peculiarities in its habits. It is found, and I believe 

 only found, in old shells of Dentalium entalis which it enters, 

 and afterwards seals up with a strong and immovable plug 

 of cemented sand, leaving a small circular hole on one side 

 through which to protrude the long proboscis in search of 

 prey, and yet doubtless too narrow to permit the entrance of 

 a foe. Is it not to be admired that a helpless worm should 

 find prepared for it a residence and stronghold adapted to its 

 wants, yet fabricated by another creature of very different 

 structure and habits ? 



Siphunculus Dentalii is of frequent occurrence in Berwick 

 Bay. When the proboscis is retracted, the body is about 

 three quarters of an inch long, subcylindrical, white, opaque, 

 obtuse at both ends ; and to the unaided eye little further is 

 apparent. The magnifier shows it to be slightly wrinkled, 

 or annulated, covered all over with minute close-set tubercles, 

 and furnished towards the middle with a broad belt of larger 



